Accession Number : ADA292804

Title :   The Structure and Reactivity of Boron and Carbon Surfaces.

Descriptive Note : Final technical rept. 15 Mar 92-14 Sep 94,

Corporate Author : ILLINOIS UNIV AT URBANA DEPT OF CHEMISTRY

Personal Author(s) : Trenary, Michael

PDF Url : ADA292804

Report Date : 22 FEB 1995

Pagination or Media Count : 6

Abstract : Research funded by this grant focused on three areas: First, we have explored the surface chemistry associated with reactions of O2, D2O, B2O2 and B203 with boron thin films grown on Ta(110) through the thermal decomposition of diborane. These reactions were studied mainly with the techniques of X-ray photoelectron spectroscopy and mass analyzed thermal desorption. We find that both O2 and D2O form a B2O3-like oxide on the surface but that the oxide desorbs mainly as B2O2. Second, we have studied the reaction of B2O3 and O2 with graphitic carbon deposited on the Pt(111) surface. Although B2O3 is known to inhibit the oxidation of carbon/carbon composites, we found that B2O3 deposited on a carbon layer on Pt(111) completely removes the surface carbon by oxidizing it at 1000 K to CO(g). Although we also observe the desorption of B2O2(g) from the surface, we determined that the B2O3 is reduced in the process to elemental boron. Third, we finished some experiments during the first few months of the grant on the oxidation of the LaB6(100) surface. jg

Descriptors :   *REACTIVITIES, *CARBON CARBON COMPOSITES, *MOLECULAR STRUCTURE, *BORON, THIN FILMS, GRAPHITE, SURFACES, OXIDATION, X RAY PHOTOELECTRON SPECTROSCOPY, SURFACE CHEMISTRY, DESORPTION, TANTALUM, PYROLYSIS, THERMAL RADIATION, DIBORANES.

Subject Categories : Inorganic Chemistry
      Physical Chemistry
      Laminates and Composite Materials
      Atomic and Molecular Physics and Spectroscopy
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE